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-rw-r--r--arch/powerpc/kvm/book3s_64_mmu_hv.c919
1 files changed, 881 insertions, 38 deletions
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index bc3a2ea94217..ddc485a529f2 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -23,6 +23,7 @@
#include <linux/gfp.h>
#include <linux/slab.h>
#include <linux/hugetlb.h>
+#include <linux/vmalloc.h>
#include <asm/tlbflush.h>
#include <asm/kvm_ppc.h>
@@ -33,15 +34,6 @@
#include <asm/ppc-opcode.h>
#include <asm/cputable.h>
-/* For now use fixed-size 16MB page table */
-#define HPT_ORDER 24
-#define HPT_NPTEG (1ul << (HPT_ORDER - 7)) /* 128B per pteg */
-#define HPT_HASH_MASK (HPT_NPTEG - 1)
-
-/* Pages in the VRMA are 16MB pages */
-#define VRMA_PAGE_ORDER 24
-#define VRMA_VSID 0x1ffffffUL /* 1TB VSID reserved for VRMA */
-
/* POWER7 has 10-bit LPIDs, PPC970 has 6-bit LPIDs */
#define MAX_LPID_970 63
#define NR_LPIDS (LPID_RSVD + 1)
@@ -51,21 +43,41 @@ long kvmppc_alloc_hpt(struct kvm *kvm)
{
unsigned long hpt;
unsigned long lpid;
+ struct revmap_entry *rev;
+ struct kvmppc_linear_info *li;
+
+ /* Allocate guest's hashed page table */
+ li = kvm_alloc_hpt();
+ if (li) {
+ /* using preallocated memory */
+ hpt = (ulong)li->base_virt;
+ kvm->arch.hpt_li = li;
+ } else {
+ /* using dynamic memory */
+ hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_REPEAT|
+ __GFP_NOWARN, HPT_ORDER - PAGE_SHIFT);
+ }
- hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_REPEAT|__GFP_NOWARN,
- HPT_ORDER - PAGE_SHIFT);
if (!hpt) {
pr_err("kvm_alloc_hpt: Couldn't alloc HPT\n");
return -ENOMEM;
}
kvm->arch.hpt_virt = hpt;
+ /* Allocate reverse map array */
+ rev = vmalloc(sizeof(struct revmap_entry) * HPT_NPTE);
+ if (!rev) {
+ pr_err("kvmppc_alloc_hpt: Couldn't alloc reverse map array\n");
+ goto out_freehpt;
+ }
+ kvm->arch.revmap = rev;
+
+ /* Allocate the guest's logical partition ID */
do {
lpid = find_first_zero_bit(lpid_inuse, NR_LPIDS);
if (lpid >= NR_LPIDS) {
pr_err("kvm_alloc_hpt: No LPIDs free\n");
- free_pages(hpt, HPT_ORDER - PAGE_SHIFT);
- return -ENOMEM;
+ goto out_freeboth;
}
} while (test_and_set_bit(lpid, lpid_inuse));
@@ -74,37 +86,64 @@ long kvmppc_alloc_hpt(struct kvm *kvm)
pr_info("KVM guest htab at %lx, LPID %lx\n", hpt, lpid);
return 0;
+
+ out_freeboth:
+ vfree(rev);
+ out_freehpt:
+ free_pages(hpt, HPT_ORDER - PAGE_SHIFT);
+ return -ENOMEM;
}
void kvmppc_free_hpt(struct kvm *kvm)
{
clear_bit(kvm->arch.lpid, lpid_inuse);
- free_pages(kvm->arch.hpt_virt, HPT_ORDER - PAGE_SHIFT);
+ vfree(kvm->arch.revmap);
+ if (kvm->arch.hpt_li)
+ kvm_release_hpt(kvm->arch.hpt_li);
+ else
+ free_pages(kvm->arch.hpt_virt, HPT_ORDER - PAGE_SHIFT);
+}
+
+/* Bits in first HPTE dword for pagesize 4k, 64k or 16M */
+static inline unsigned long hpte0_pgsize_encoding(unsigned long pgsize)
+{
+ return (pgsize > 0x1000) ? HPTE_V_LARGE : 0;
+}
+
+/* Bits in second HPTE dword for pagesize 4k, 64k or 16M */
+static inline unsigned long hpte1_pgsize_encoding(unsigned long pgsize)
+{
+ return (pgsize == 0x10000) ? 0x1000 : 0;
}
-void kvmppc_map_vrma(struct kvm *kvm, struct kvm_userspace_memory_region *mem)
+void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot,
+ unsigned long porder)
{
unsigned long i;
- unsigned long npages = kvm->arch.ram_npages;
- unsigned long pfn;
- unsigned long *hpte;
- unsigned long hash;
- struct kvmppc_pginfo *pginfo = kvm->arch.ram_pginfo;
+ unsigned long npages;
+ unsigned long hp_v, hp_r;
+ unsigned long addr, hash;
+ unsigned long psize;
+ unsigned long hp0, hp1;
+ long ret;
- if (!pginfo)
- return;
+ psize = 1ul << porder;
+ npages = memslot->npages >> (porder - PAGE_SHIFT);
/* VRMA can't be > 1TB */
- if (npages > 1ul << (40 - kvm->arch.ram_porder))
- npages = 1ul << (40 - kvm->arch.ram_porder);
+ if (npages > 1ul << (40 - porder))
+ npages = 1ul << (40 - porder);
/* Can't use more than 1 HPTE per HPTEG */
if (npages > HPT_NPTEG)
npages = HPT_NPTEG;
+ hp0 = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) |
+ HPTE_V_BOLTED | hpte0_pgsize_encoding(psize);
+ hp1 = hpte1_pgsize_encoding(psize) |
+ HPTE_R_R | HPTE_R_C | HPTE_R_M | PP_RWXX;
+
for (i = 0; i < npages; ++i) {
- pfn = pginfo[i].pfn;
- if (!pfn)
- break;
+ addr = i << porder;
/* can't use hpt_hash since va > 64 bits */
hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25))) & HPT_HASH_MASK;
/*
@@ -113,15 +152,15 @@ void kvmppc_map_vrma(struct kvm *kvm, struct kvm_userspace_memory_region *mem)
* at most one HPTE per HPTEG, we just assume entry 7
* is available and use it.
*/
- hpte = (unsigned long *) (kvm->arch.hpt_virt + (hash << 7));
- hpte += 7 * 2;
- /* HPTE low word - RPN, protection, etc. */
- hpte[1] = (pfn << PAGE_SHIFT) | HPTE_R_R | HPTE_R_C |
- HPTE_R_M | PP_RWXX;
- wmb();
- hpte[0] = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) |
- (i << (VRMA_PAGE_ORDER - 16)) | HPTE_V_BOLTED |
- HPTE_V_LARGE | HPTE_V_VALID;
+ hash = (hash << 3) + 7;
+ hp_v = hp0 | ((addr >> 16) & ~0x7fUL);
+ hp_r = hp1 | addr;
+ ret = kvmppc_virtmode_h_enter(vcpu, H_EXACT, hash, hp_v, hp_r);
+ if (ret != H_SUCCESS) {
+ pr_err("KVM: map_vrma at %lx failed, ret=%ld\n",
+ addr, ret);
+ break;
+ }
}
}
@@ -158,10 +197,814 @@ static void kvmppc_mmu_book3s_64_hv_reset_msr(struct kvm_vcpu *vcpu)
kvmppc_set_msr(vcpu, MSR_SF | MSR_ME);
}
+/*
+ * This is called to get a reference to a guest page if there isn't
+ * one already in the kvm->arch.slot_phys[][] arrays.
+ */
+static long kvmppc_get_guest_page(struct kvm *kvm, unsigned long gfn,
+ struct kvm_memory_slot *memslot,
+ unsigned long psize)
+{
+ unsigned long start;
+ long np, err;
+ struct page *page, *hpage, *pages[1];
+ unsigned long s, pgsize;
+ unsigned long *physp;
+ unsigned int is_io, got, pgorder;
+ struct vm_area_struct *vma;
+ unsigned long pfn, i, npages;
+
+ physp = kvm->arch.slot_phys[memslot->id];
+ if (!physp)
+ return -EINVAL;
+ if (physp[gfn - memslot->base_gfn])
+ return 0;
+
+ is_io = 0;
+ got = 0;
+ page = NULL;
+ pgsize = psize;
+ err = -EINVAL;
+ start = gfn_to_hva_memslot(memslot, gfn);
+
+ /* Instantiate and get the page we want access to */
+ np = get_user_pages_fast(start, 1, 1, pages);
+ if (np != 1) {
+ /* Look up the vma for the page */
+ down_read(&current->mm->mmap_sem);
+ vma = find_vma(current->mm, start);
+ if (!vma || vma->vm_start > start ||
+ start + psize > vma->vm_end ||
+ !(vma->vm_flags & VM_PFNMAP))
+ goto up_err;
+ is_io = hpte_cache_bits(pgprot_val(vma->vm_page_prot));
+ pfn = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
+ /* check alignment of pfn vs. requested page size */
+ if (psize > PAGE_SIZE && (pfn & ((psize >> PAGE_SHIFT) - 1)))
+ goto up_err;
+ up_read(&current->mm->mmap_sem);
+
+ } else {
+ page = pages[0];
+ got = KVMPPC_GOT_PAGE;
+
+ /* See if this is a large page */
+ s = PAGE_SIZE;
+ if (PageHuge(page)) {
+ hpage = compound_head(page);
+ s <<= compound_order(hpage);
+ /* Get the whole large page if slot alignment is ok */
+ if (s > psize && slot_is_aligned(memslot, s) &&
+ !(memslot->userspace_addr & (s - 1))) {
+ start &= ~(s - 1);
+ pgsize = s;
+ page = hpage;
+ }
+ }
+ if (s < psize)
+ goto out;
+ pfn = page_to_pfn(page);
+ }
+
+ npages = pgsize >> PAGE_SHIFT;
+ pgorder = __ilog2(npages);
+ physp += (gfn - memslot->base_gfn) & ~(npages - 1);
+ spin_lock(&kvm->arch.slot_phys_lock);
+ for (i = 0; i < npages; ++i) {
+ if (!physp[i]) {
+ physp[i] = ((pfn + i) << PAGE_SHIFT) +
+ got + is_io + pgorder;
+ got = 0;
+ }
+ }
+ spin_unlock(&kvm->arch.slot_phys_lock);
+ err = 0;
+
+ out:
+ if (got) {
+ if (PageHuge(page))
+ page = compound_head(page);
+ put_page(page);
+ }
+ return err;
+
+ up_err:
+ up_read(&current->mm->mmap_sem);
+ return err;
+}
+
+/*
+ * We come here on a H_ENTER call from the guest when we are not
+ * using mmu notifiers and we don't have the requested page pinned
+ * already.
+ */
+long kvmppc_virtmode_h_enter(struct kvm_vcpu *vcpu, unsigned long flags,
+ long pte_index, unsigned long pteh, unsigned long ptel)
+{
+ struct kvm *kvm = vcpu->kvm;
+ unsigned long psize, gpa, gfn;
+ struct kvm_memory_slot *memslot;
+ long ret;
+
+ if (kvm->arch.using_mmu_notifiers)
+ goto do_insert;
+
+ psize = hpte_page_size(pteh, ptel);
+ if (!psize)
+ return H_PARAMETER;
+
+ pteh &= ~(HPTE_V_HVLOCK | HPTE_V_ABSENT | HPTE_V_VALID);
+
+ /* Find the memslot (if any) for this address */
+ gpa = (ptel & HPTE_R_RPN) & ~(psize - 1);
+ gfn = gpa >> PAGE_SHIFT;
+ memslot = gfn_to_memslot(kvm, gfn);
+ if (memslot && !(memslot->flags & KVM_MEMSLOT_INVALID)) {
+ if (!slot_is_aligned(memslot, psize))
+ return H_PARAMETER;
+ if (kvmppc_get_guest_page(kvm, gfn, memslot, psize) < 0)
+ return H_PARAMETER;
+ }
+
+ do_insert:
+ /* Protect linux PTE lookup from page table destruction */
+ rcu_read_lock_sched(); /* this disables preemption too */
+ vcpu->arch.pgdir = current->mm->pgd;
+ ret = kvmppc_h_enter(vcpu, flags, pte_index, pteh, ptel);
+ rcu_read_unlock_sched();
+ if (ret == H_TOO_HARD) {
+ /* this can't happen */
+ pr_err("KVM: Oops, kvmppc_h_enter returned too hard!\n");
+ ret = H_RESOURCE; /* or something */
+ }
+ return ret;
+
+}
+
+static struct kvmppc_slb *kvmppc_mmu_book3s_hv_find_slbe(struct kvm_vcpu *vcpu,
+ gva_t eaddr)
+{
+ u64 mask;
+ int i;
+
+ for (i = 0; i < vcpu->arch.slb_nr; i++) {
+ if (!(vcpu->arch.slb[i].orige & SLB_ESID_V))
+ continue;
+
+ if (vcpu->arch.slb[i].origv & SLB_VSID_B_1T)
+ mask = ESID_MASK_1T;
+ else
+ mask = ESID_MASK;
+
+ if (((vcpu->arch.slb[i].orige ^ eaddr) & mask) == 0)
+ return &vcpu->arch.slb[i];
+ }
+ return NULL;
+}
+
+static unsigned long kvmppc_mmu_get_real_addr(unsigned long v, unsigned long r,
+ unsigned long ea)
+{
+ unsigned long ra_mask;
+
+ ra_mask = hpte_page_size(v, r) - 1;
+ return (r & HPTE_R_RPN & ~ra_mask) | (ea & ra_mask);
+}
+
static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
- struct kvmppc_pte *gpte, bool data)
+ struct kvmppc_pte *gpte, bool data)
+{
+ struct kvm *kvm = vcpu->kvm;
+ struct kvmppc_slb *slbe;
+ unsigned long slb_v;
+ unsigned long pp, key;
+ unsigned long v, gr;
+ unsigned long *hptep;
+ int index;
+ int virtmode = vcpu->arch.shregs.msr & (data ? MSR_DR : MSR_IR);
+
+ /* Get SLB entry */
+ if (virtmode) {
+ slbe = kvmppc_mmu_book3s_hv_find_slbe(vcpu, eaddr);
+ if (!slbe)
+ return -EINVAL;
+ slb_v = slbe->origv;
+ } else {
+ /* real mode access */
+ slb_v = vcpu->kvm->arch.vrma_slb_v;
+ }
+
+ /* Find the HPTE in the hash table */
+ index = kvmppc_hv_find_lock_hpte(kvm, eaddr, slb_v,
+ HPTE_V_VALID | HPTE_V_ABSENT);
+ if (index < 0)
+ return -ENOENT;
+ hptep = (unsigned long *)(kvm->arch.hpt_virt + (index << 4));
+ v = hptep[0] & ~HPTE_V_HVLOCK;
+ gr = kvm->arch.revmap[index].guest_rpte;
+
+ /* Unlock the HPTE */
+ asm volatile("lwsync" : : : "memory");
+ hptep[0] = v;
+
+ gpte->eaddr = eaddr;
+ gpte->vpage = ((v & HPTE_V_AVPN) << 4) | ((eaddr >> 12) & 0xfff);
+
+ /* Get PP bits and key for permission check */
+ pp = gr & (HPTE_R_PP0 | HPTE_R_PP);
+ key = (vcpu->arch.shregs.msr & MSR_PR) ? SLB_VSID_KP : SLB_VSID_KS;
+ key &= slb_v;
+
+ /* Calculate permissions */
+ gpte->may_read = hpte_read_permission(pp, key);
+ gpte->may_write = hpte_write_permission(pp, key);
+ gpte->may_execute = gpte->may_read && !(gr & (HPTE_R_N | HPTE_R_G));
+
+ /* Storage key permission check for POWER7 */
+ if (data && virtmode && cpu_has_feature(CPU_FTR_ARCH_206)) {
+ int amrfield = hpte_get_skey_perm(gr, vcpu->arch.amr);
+ if (amrfield & 1)
+ gpte->may_read = 0;
+ if (amrfield & 2)
+ gpte->may_write = 0;
+ }
+
+ /* Get the guest physical address */
+ gpte->raddr = kvmppc_mmu_get_real_addr(v, gr, eaddr);
+ return 0;
+}
+
+/*
+ * Quick test for whether an instruction is a load or a store.
+ * If the instruction is a load or a store, then this will indicate
+ * which it is, at least on server processors. (Embedded processors
+ * have some external PID instructions that don't follow the rule
+ * embodied here.) If the instruction isn't a load or store, then
+ * this doesn't return anything useful.
+ */
+static int instruction_is_store(unsigned int instr)
+{
+ unsigned int mask;
+
+ mask = 0x10000000;
+ if ((instr & 0xfc000000) == 0x7c000000)
+ mask = 0x100; /* major opcode 31 */
+ return (instr & mask) != 0;
+}
+
+static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu,
+ unsigned long gpa, int is_store)
+{
+ int ret;
+ u32 last_inst;
+ unsigned long srr0 = kvmppc_get_pc(vcpu);
+
+ /* We try to load the last instruction. We don't let
+ * emulate_instruction do it as it doesn't check what
+ * kvmppc_ld returns.
+ * If we fail, we just return to the guest and try executing it again.
+ */
+ if (vcpu->arch.last_inst == KVM_INST_FETCH_FAILED) {
+ ret = kvmppc_ld(vcpu, &srr0, sizeof(u32), &last_inst, false);
+ if (ret != EMULATE_DONE || last_inst == KVM_INST_FETCH_FAILED)
+ return RESUME_GUEST;
+ vcpu->arch.last_inst = last_inst;
+ }
+
+ /*
+ * WARNING: We do not know for sure whether the instruction we just
+ * read from memory is the same that caused the fault in the first
+ * place. If the instruction we read is neither an load or a store,
+ * then it can't access memory, so we don't need to worry about
+ * enforcing access permissions. So, assuming it is a load or
+ * store, we just check that its direction (load or store) is
+ * consistent with the original fault, since that's what we
+ * checked the access permissions against. If there is a mismatch
+ * we just return and retry the instruction.
+ */
+
+ if (instruction_is_store(vcpu->arch.last_inst) != !!is_store)
+ return RESUME_GUEST;
+
+ /*
+ * Emulated accesses are emulated by looking at the hash for
+ * translation once, then performing the access later. The
+ * translation could be invalidated in the meantime in which
+ * point performing the subsequent memory access on the old
+ * physical address could possibly be a security hole for the
+ * guest (but not the host).
+ *
+ * This is less of an issue for MMIO stores since they aren't
+ * globally visible. It could be an issue for MMIO loads to
+ * a certain extent but we'll ignore it for now.
+ */
+
+ vcpu->arch.paddr_accessed = gpa;
+ return kvmppc_emulate_mmio(run, vcpu);
+}
+
+int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
+ unsigned long ea, unsigned long dsisr)
+{
+ struct kvm *kvm = vcpu->kvm;
+ unsigned long *hptep, hpte[3], r;
+ unsigned long mmu_seq, psize, pte_size;
+ unsigned long gfn, hva, pfn;
+ struct kvm_memory_slot *memslot;
+ unsigned long *rmap;
+ struct revmap_entry *rev;
+ struct page *page, *pages[1];
+ long index, ret, npages;
+ unsigned long is_io;
+ unsigned int writing, write_ok;
+ struct vm_area_struct *vma;
+ unsigned long rcbits;
+
+ /*
+ * Real-mode code has already searched the HPT and found the
+ * entry we're interested in. Lock the entry and check that
+ * it hasn't changed. If it has, just return and re-execute the
+ * instruction.
+ */
+ if (ea != vcpu->arch.pgfault_addr)
+ return RESUME_GUEST;
+ index = vcpu->arch.pgfault_index;
+ hptep = (unsigned long *)(kvm->arch.hpt_virt + (index << 4));
+ rev = &kvm->arch.revmap[index];
+ preempt_disable();
+ while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
+ cpu_relax();
+ hpte[0] = hptep[0] & ~HPTE_V_HVLOCK;
+ hpte[1] = hptep[1];
+ hpte[2] = r = rev->guest_rpte;
+ asm volatile("lwsync" : : : "memory");
+ hptep[0] = hpte[0];
+ preempt_enable();
+
+ if (hpte[0] != vcpu->arch.pgfault_hpte[0] ||
+ hpte[1] != vcpu->arch.pgfault_hpte[1])
+ return RESUME_GUEST;
+
+ /* Translate the logical address and get the page */
+ psize = hpte_page_size(hpte[0], r);
+ gfn = hpte_rpn(r, psize);
+ memslot = gfn_to_memslot(kvm, gfn);
+
+ /* No memslot means it's an emulated MMIO region */
+ if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) {
+ unsigned long gpa = (gfn << PAGE_SHIFT) | (ea & (psize - 1));
+ return kvmppc_hv_emulate_mmio(run, vcpu, gpa,
+ dsisr & DSISR_ISSTORE);
+ }
+
+ if (!kvm->arch.using_mmu_notifiers)
+ return -EFAULT; /* should never get here */
+
+ /* used to check for invalidations in progress */
+ mmu_seq = kvm->mmu_notifier_seq;
+ smp_rmb();
+
+ is_io = 0;
+ pfn = 0;
+ page = NULL;
+ pte_size = PAGE_SIZE;
+ writing = (dsisr & DSISR_ISSTORE) != 0;
+ /* If writing != 0, then the HPTE must allow writing, if we get here */
+ write_ok = writing;
+ hva = gfn_to_hva_memslot(memslot, gfn);
+ npages = get_user_pages_fast(hva, 1, writing, pages);
+ if (npages < 1) {
+ /* Check if it's an I/O mapping */
+ down_read(&current->mm->mmap_sem);
+ vma = find_vma(current->mm, hva);
+ if (vma && vma->vm_start <= hva && hva + psize <= vma->vm_end &&
+ (vma->vm_flags & VM_PFNMAP)) {
+ pfn = vma->vm_pgoff +
+ ((hva - vma->vm_start) >> PAGE_SHIFT);
+ pte_size = psize;
+ is_io = hpte_cache_bits(pgprot_val(vma->vm_page_prot));
+ write_ok = vma->vm_flags & VM_WRITE;
+ }
+ up_read(&current->mm->mmap_sem);
+ if (!pfn)
+ return -EFAULT;
+ } else {
+ page = pages[0];
+ if (PageHuge(page)) {
+ page = compound_head(page);
+ pte_size <<= compound_order(page);
+ }
+ /* if the guest wants write access, see if that is OK */
+ if (!writing && hpte_is_writable(r)) {
+ pte_t *ptep, pte;
+
+ /*
+ * We need to protect against page table destruction
+ * while looking up and updating the pte.
+ */
+ rcu_read_lock_sched();
+ ptep = find_linux_pte_or_hugepte(current->mm->pgd,
+ hva, NULL);
+ if (ptep && pte_present(*ptep)) {
+ pte = kvmppc_read_update_linux_pte(ptep, 1);
+ if (pte_write(pte))
+ write_ok = 1;
+ }
+ rcu_read_unlock_sched();
+ }
+ pfn = page_to_pfn(page);
+ }
+
+ ret = -EFAULT;
+ if (psize > pte_size)
+ goto out_put;
+
+ /* Check WIMG vs. the actual page we're accessing */
+ if (!hpte_cache_flags_ok(r, is_io)) {
+ if (is_io)
+ return -EFAULT;
+ /*
+ * Allow guest to map emulated device memory as
+ * uncacheable, but actually make it cacheable.
+ */
+ r = (r & ~(HPTE_R_W|HPTE_R_I|HPTE_R_G)) | HPTE_R_M;
+ }
+
+ /* Set the HPTE to point to pfn */
+ r = (r & ~(HPTE_R_PP0 - pte_size)) | (pfn << PAGE_SHIFT);
+ if (hpte_is_writable(r) && !write_ok)
+ r = hpte_make_readonly(r);
+ ret = RESUME_GUEST;
+ preempt_disable();
+ while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
+ cpu_relax();
+ if ((hptep[0] & ~HPTE_V_HVLOCK) != hpte[0] || hptep[1] != hpte[1] ||
+ rev->guest_rpte != hpte[2])
+ /* HPTE has been changed under us; let the guest retry */
+ goto out_unlock;
+ hpte[0] = (hpte[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID;
+
+ rmap = &memslot->rmap[gfn - memslot->base_gfn];
+ lock_rmap(rmap);
+
+ /* Check if we might have been invalidated; let the guest retry if so */
+ ret = RESUME_GUEST;
+ if (mmu_notifier_retry(vcpu, mmu_seq)) {
+ unlock_rmap(rmap);
+ goto out_unlock;
+ }
+
+ /* Only set R/C in real HPTE if set in both *rmap and guest_rpte */
+ rcbits = *rmap >> KVMPPC_RMAP_RC_SHIFT;
+ r &= rcbits | ~(HPTE_R_R | HPTE_R_C);
+
+ if (hptep[0] & HPTE_V_VALID) {
+ /* HPTE was previously valid, so we need to invalidate it */
+ unlock_rmap(rmap);
+ hptep[0] |= HPTE_V_ABSENT;
+ kvmppc_invalidate_hpte(kvm, hptep, index);
+ /* don't lose previous R and C bits */
+ r |= hptep[1] & (HPTE_R_R | HPTE_R_C);
+ } else {
+ kvmppc_add_revmap_chain(kvm, rev, rmap, index, 0);
+ }
+
+ hptep[1] = r;
+ eieio();
+ hptep[0] = hpte[0];
+ asm volatile("ptesync" : : : "memory");
+ preempt_enable();
+ if (page && hpte_is_writable(r))
+ SetPageDirty(page);
+
+ out_put:
+ if (page)
+ put_page(page);
+ return ret;
+
+ out_unlock:
+ hptep[0] &= ~HPTE_V_HVLOCK;
+ preempt_enable();
+ goto out_put;
+}
+
+static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
+ int (*handler)(struct kvm *kvm, unsigned long *rmapp,
+ unsigned long gfn))
+{
+ int ret;
+ int retval = 0;
+ struct kvm_memslots *slots;
+ struct kvm_memory_slot *memslot;
+
+ slots = kvm_memslots(kvm);
+ kvm_for_each_memslot(memslot, slots) {
+ unsigned long start = memslot->userspace_addr;
+ unsigned long end;
+
+ end = start + (memslot->npages << PAGE_SHIFT);
+ if (hva >= start && hva < end) {
+ gfn_t gfn_offset = (hva - start) >> PAGE_SHIFT;
+
+ ret = handler(kvm, &memslot->rmap[gfn_offset],
+ memslot->base_gfn + gfn_offset);
+ retval |= ret;
+ }
+ }
+
+ return retval;
+}
+
+static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp,
+ unsigned long gfn)
+{
+ struct revmap_entry *rev = kvm->arch.revmap;
+ unsigned long h, i, j;
+ unsigned long *hptep;
+ unsigned long ptel, psize, rcbits;
+
+ for (;;) {
+ lock_rmap(rmapp);
+ if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
+ unlock_rmap(rmapp);
+ break;
+ }
+
+ /*
+ * To avoid an ABBA deadlock with the HPTE lock bit,
+ * we can't spin on the HPTE lock while holding the
+ * rmap chain lock.
+ */
+ i = *rmapp & KVMPPC_RMAP_INDEX;
+ hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4));
+ if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
+ /* unlock rmap before spinning on the HPTE lock */
+ unlock_rmap(rmapp);
+ while (hptep[0] & HPTE_V_HVLOCK)
+ cpu_relax();
+ continue;
+ }
+ j = rev[i].forw;
+ if (j == i) {
+ /* chain is now empty */
+ *rmapp &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX);
+ } else {
+ /* remove i from chain */
+ h = rev[i].back;
+ rev[h].forw = j;
+ rev[j].back = h;
+ rev[i].forw = rev[i].back = i;
+ *rmapp = (*rmapp & ~KVMPPC_RMAP_INDEX) | j;
+ }
+
+ /* Now check and modify the HPTE */
+ ptel = rev[i].guest_rpte;
+ psize = hpte_page_size(hptep[0], ptel);
+ if ((hptep[0] & HPTE_V_VALID) &&
+ hpte_rpn(ptel, psize) == gfn) {
+ hptep[0] |= HPTE_V_ABSENT;
+ kvmppc_invalidate_hpte(kvm, hptep, i);
+ /* Harvest R and C */
+ rcbits = hptep[1] & (HPTE_R_R | HPTE_R_C);
+ *rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT;
+ rev[i].guest_rpte = ptel | rcbits;
+ }
+ unlock_rmap(rmapp);
+ hptep[0] &= ~HPTE_V_HVLOCK;
+ }
+ return 0;
+}
+
+int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
+{
+ if (kvm->arch.using_mmu_notifiers)
+ kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
+ return 0;
+}
+
+static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
+ unsigned long gfn)
+{
+ struct revmap_entry *rev = kvm->arch.revmap;
+ unsigned long head, i, j;
+ unsigned long *hptep;
+ int ret = 0;
+
+ retry:
+ lock_rmap(rmapp);
+ if (*rmapp & KVMPPC_RMAP_REFERENCED) {
+ *rmapp &= ~KVMPPC_RMAP_REFERENCED;
+ ret = 1;
+ }
+ if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
+ unlock_rmap(rmapp);
+ return ret;
+ }
+
+ i = head = *rmapp & KVMPPC_RMAP_INDEX;
+ do {
+ hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4));
+ j = rev[i].forw;
+
+ /* If this HPTE isn't referenced, ignore it */
+ if (!(hptep[1] & HPTE_R_R))
+ continue;
+
+ if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
+ /* unlock rmap before spinning on the HPTE lock */
+ unlock_rmap(rmapp);
+ while (hptep[0] & HPTE_V_HVLOCK)
+ cpu_relax();
+ goto retry;
+ }
+
+ /* Now check and modify the HPTE */
+ if ((hptep[0] & HPTE_V_VALID) && (hptep[1] & HPTE_R_R)) {
+ kvmppc_clear_ref_hpte(kvm, hptep, i);
+ rev[i].guest_rpte |= HPTE_R_R;
+ ret = 1;
+ }
+ hptep[0] &= ~HPTE_V_HVLOCK;
+ } while ((i = j) != head);
+
+ unlock_rmap(rmapp);
+ return ret;
+}
+
+int kvm_age_hva(struct kvm *kvm, unsigned long hva)
+{
+ if (!kvm->arch.using_mmu_notifiers)
+ return 0;
+ return kvm_handle_hva(kvm, hva, kvm_age_rmapp);
+}
+
+static int kvm_test_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
+ unsigned long gfn)
+{
+ struct revmap_entry *rev = kvm->arch.revmap;
+ unsigned long head, i, j;
+ unsigned long *hp;
+ int ret = 1;
+
+ if (*rmapp & KVMPPC_RMAP_REFERENCED)
+ return 1;
+
+ lock_rmap(rmapp);
+ if (*rmapp & KVMPPC_RMAP_REFERENCED)
+ goto out;
+
+ if (*rmapp & KVMPPC_RMAP_PRESENT) {
+ i = head = *rmapp & KVMPPC_RMAP_INDEX;
+ do {
+ hp = (unsigned long *)(kvm->arch.hpt_virt + (i << 4));
+ j = rev[i].forw;
+ if (hp[1] & HPTE_R_R)
+ goto out;
+ } while ((i = j) != head);
+ }
+ ret = 0;
+
+ out:
+ unlock_rmap(rmapp);
+ return ret;
+}
+
+int kvm_test_age_hva(struct kvm *kvm, unsigned long hva)
+{
+ if (!kvm->arch.using_mmu_notifiers)
+ return 0;
+ return kvm_handle_hva(kvm, hva, kvm_test_age_rmapp);
+}
+
+void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
{
- return -ENOENT;
+ if (!kvm->arch.using_mmu_notifiers)
+ return;
+ kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
+}
+
+static int kvm_test_clear_dirty(struct kvm *kvm, unsigned long *rmapp)
+{
+ struct revmap_entry *rev = kvm->arch.revmap;
+ unsigned long head, i, j;
+ unsigned long *hptep;
+ int ret = 0;
+
+ retry:
+ lock_rmap(rmapp);
+ if (*rmapp & KVMPPC_RMAP_CHANGED) {
+ *rmapp &= ~KVMPPC_RMAP_CHANGED;
+ ret = 1;
+ }
+ if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
+ unlock_rmap(rmapp);
+ return ret;
+ }
+
+ i = head = *rmapp & KVMPPC_RMAP_INDEX;
+ do {
+ hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4));
+ j = rev[i].forw;
+
+ if (!(hptep[1] & HPTE_R_C))
+ continue;
+
+ if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
+ /* unlock rmap before spinning on the HPTE lock */
+ unlock_rmap(rmapp);
+ while (hptep[0] & HPTE_V_HVLOCK)
+ cpu_relax();
+ goto retry;
+ }
+
+ /* Now check and modify the HPTE */
+ if ((hptep[0] & HPTE_V_VALID) && (hptep[1] & HPTE_R_C)) {
+ /* need to make it temporarily absent to clear C */
+ hptep[0] |= HPTE_V_ABSENT;
+ kvmppc_invalidate_hpte(kvm, hptep, i);
+ hptep[1] &= ~HPTE_R_C;
+ eieio();
+ hptep[0] = (hptep[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID;
+ rev[i].guest_rpte |= HPTE_R_C;
+ ret = 1;
+ }
+ hptep[0] &= ~HPTE_V_HVLOCK;
+ } while ((i = j) != head);
+
+ unlock_rmap(rmapp);
+ return ret;
+}
+
+long kvmppc_hv_get_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot)
+{
+ unsigned long i;
+ unsigned long *rmapp, *map;
+
+ preempt_disable();
+ rmapp = memslot->rmap;
+ map = memslot->dirty_bitmap;
+ for (i = 0; i < memslot->npages; ++i) {
+ if (kvm_test_clear_dirty(kvm, rmapp))
+ __set_bit_le(i, map);
+ ++rmapp;
+ }
+ preempt_enable();
+ return 0;
+}
+
+void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa,
+ unsigned long *nb_ret)
+{
+ struct kvm_memory_slot *memslot;
+ unsigned long gfn = gpa >> PAGE_SHIFT;
+ struct page *page, *pages[1];
+ int npages;
+ unsigned long hva, psize, offset;
+ unsigned long pa;
+ unsigned long *physp;
+
+ memslot = gfn_to_memslot(kvm, gfn);
+ if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
+ return NULL;
+ if (!kvm->arch.using_mmu_notifiers) {
+ physp = kvm->arch.slot_phys[memslot->id];
+ if (!physp)
+ return NULL;
+ physp += gfn - memslot->base_gfn;
+ pa = *physp;
+ if (!pa) {
+ if (kvmppc_get_guest_page(kvm, gfn, memslot,
+ PAGE_SIZE) < 0)
+ return NULL;
+ pa = *physp;
+ }
+ page = pfn_to_page(pa >> PAGE_SHIFT);
+ } else {
+ hva = gfn_to_hva_memslot(memslot, gfn);
+ npages = get_user_pages_fast(hva, 1, 1, pages);
+ if (npages < 1)
+ return NULL;
+ page = pages[0];
+ }
+ psize = PAGE_SIZE;
+ if (PageHuge(page)) {
+ page = compound_head(page);
+ psize <<= compound_order(page);
+ }
+ if (!kvm->arch.using_mmu_notifiers)
+ get_page(page);
+ offset = gpa & (psize - 1);
+ if (nb_ret)
+ *nb_ret = psize - offset;
+ return page_address(page) + offset;
+}
+
+void kvmppc_unpin_guest_page(struct kvm *kvm, void *va)
+{
+ struct page *page = virt_to_page(va);
+
+ page = compound_head(page);
+ put_page(page);
}
void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu)
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.